Placebo treatment in congestive heart failure

In order to evaluate the effect of placebo treatment in congestive heart failure, we retrospectively studied 24 patients with moderately severe congestive heart failure who participated in heart failure treatment trials performed over the past 10 years in the Ohio State University Heart Failure Research Laboratory. Placebo-treated patients from 4 placebo-controlled trials comprised the placebo treatment group (n = 15), while one natural course-controlled trial provided patients for the non-placebo control group (n = 9). Changes in symptoms, left ventricular function and exercise duration were assessed following an 8-week course of therapy. Chronic placebo therapy resulted in an 81-second improvement in exercise duration which was statistically significant when compared to pretreatment baseline and to the duration achieved by the nonplacebo control group. Clinically, functional class improved significantly by 27% above baseline only for the placebo treatment group. Indices of left ventricular function did not change for either group. The salient feature of this study is that the placebo treatment effect, while believed to exist in congestive heart failure, has never been demonstrated in a manner which controlled for the natural course and variability of the disease process. The operative components of the placebo effect remain unknown, and further investigation will be necessary to elucidate the underlying mechanisms involved. However, the importance of this phenomenon lies not only with the response to and effects of placebo therapy but also in the role that the placebo effect plays in what is generally presumed to be the predominant responses, effects and benefits of active drug therapy.